1. Field of the Invention
The present invention relates to an insulation structure and an insulation method appropriate to an ion implantation apparatus or an extraction electrode system in an ion source of the ion implantation apparatus.
2. Description of the Related Art
An ion source is provided with an extraction electrode system adapted to extract an ion beam. The extraction electrode system includes several electrodes, and one electrode is supported to the other electrode or a surrounding structure by an insulator.
Depending on a material for the ion beam and a configuration of the ion source, conductive contamination particles are extracted together with the ion beam. Deposition of the contamination particles can form a conductive path on a surface of the insulator. Sufficient insulation cannot be maintained, which may impair normal operations of an apparatus. In a case where a large amount of contamination particles are generated, frequent maintenance of the insulation part is required, and an operation ratio of the apparatus is lowered.